1.A cylindrical specimen ofcold-worked copper has ductility (%EL) of 15%. If its coldworked radius is 6.4 mm (0.25in.), what was its radius before deformation?
2.A 2in cube coal specimen, which was tested in a lab, failed at 8,000lb. A set of main entries is to be designed through the 5ft seam from which the specimen was extracted. If there is 500ft of overburden, and assuming a 50% recovery, what will be the least pillar dimension?